Within Code Assistants
Does faster coding mean better programming?
Faster task completion can be real while leaving developers less able to explain, maintain, or safely change the code they accepted.
On this page
- What controlled productivity studies actually measure
- Why working code is not the same as understood code
- Questions developers should answer before accepting a suggestion
Page outline Jump by section
Introduction
Coding assistants such as GitHub Copilot can make developers noticeably faster. The strongest controlled experiment found that programmers using Copilot completed a coding task about 56% faster than a control group. That result is real and important. However, faster completion is not the same thing as deeper understanding. A developer can successfully ship code, pass tests, and close a ticket while remaining unable to explain why the solution works, how it might fail, or how to modify it safely later. [arXiv]arxiv.orgarXiv The Impact of AI on Developer Productivity: Evidence from Git Hub CopilotThe Impact of AI on Developer Productivity: Evidence from GitHub CopilotFebruary 13, 2023…
This distinction matters because software engineering is not only about producing code. It also involves reasoning about behaviour, diagnosing failures, evaluating trade-offs, and maintaining systems over time. The central question is therefore not whether Copilot increases speed—it often does—but whether that speed sometimes masks shallow understanding.
Does faster coding mean better programming?
The most widely cited evidence for Copilot’s productivity benefits comes from a controlled GitHub study in which developers implemented an HTTP server in JavaScript. Participants with Copilot completed the task 55.8% faster than those without it. [arXiv]arxiv.orgarXiv The Impact of AI on Developer Productivity: Evidence from Git Hub CopilotThe Impact of AI on Developer Productivity: Evidence from GitHub CopilotFebruary 13, 2023…
What this study measured, however, was task completion speed under controlled conditions. It did not directly measure long-term comprehension, architectural judgement, debugging skill, or the ability to explain generated code. Those are separate capabilities.
This distinction becomes clearer when examining later research and field studies. Real-world software development involves understanding existing systems, collaborating with colleagues, reviewing code, and maintaining software months or years after it is written. Researchers studying Copilot in a large public-sector software organisation found that developers often reported feeling more productive, yet commit-based productivity metrics showed no statistically significant change after adoption. The researchers noted a gap between subjective impressions of productivity and measurable engineering output. [arXiv]arxiv.orgDeveloper Productivity With and Without GitHub Copilot: A Longitudinal Mixed-Methods Case StudySeptember 24, 2025…
The lesson is not that productivity gains are imaginary. Rather, speed measurements answer a narrower question than many people assume. They show that developers can often produce code more quickly, not that they have become better programmers in every relevant sense.
What controlled productivity studies actually measure
A common misunderstanding is to treat productivity studies as proof of increased expertise. Most studies do not measure expertise directly.
Typically, they evaluate outcomes such as:
- Time required to complete a programming task.
- Whether a solution works.
- Self-reported satisfaction.
- Perceived productivity.
- Short-term task success.
These are valuable metrics, but they do not reveal whether a developer could:
- Recreate the solution without assistance.
- Explain the reasoning behind the implementation.
- Identify hidden edge cases.
- Evaluate security implications.
- Safely modify the code six months later.
The distinction is similar to using a calculator. Completing arithmetic faster does not necessarily demonstrate a stronger understanding of mathematics. Likewise, generating code faster does not automatically demonstrate stronger software engineering judgement.
Several researchers and industry observers have therefore argued that coding-assistant studies should not be interpreted as comprehensive measures of engineering competence. [third-bit.com]third-bit.comThe task was…Read more…
Why working code is not the same as understood code
A generated solution can appear convincing long before it is fully understood.
One reason is automation bias: people tend to trust outputs produced by automated systems, especially when those outputs look polished and plausible. Research examining programmers reviewing Copilot-generated code found that developers devoted less visual attention to AI-generated code than to human-written code, despite the need for careful inspection. The authors warned that programmers should be alert to complacency when reviewing generated output. [arXiv]arxiv.orgHow Readable is Model-generated Code? Examining Readability and Visual Inspection of GitHub CopilotAugust 31, 2022…
This creates a subtle failure mode:
- The assistant proposes a solution.
- The code compiles and passes basic tests.
- The developer accepts it quickly.
- Understanding is assumed rather than verified.
The result may be functioning software accompanied by weak mental models. A programmer knows that the code works but cannot clearly explain why it works.
This becomes especially risky when the code handles concurrency, security, networking, database interactions, or unfamiliar libraries. In such situations, understanding the mechanism is often more important than obtaining a working snippet.
Evidence that comprehension can lag behind assistance
Recent research has begun examining understanding directly rather than treating task completion as a proxy.
A 2026 randomised controlled study reported that developers using AI coding assistance while learning unfamiliar programming libraries scored lower on comprehension assessments than those who worked without such assistance. The study found a divide between developers who used AI primarily for conceptual guidance and those who delegated substantial code generation. Participants who relied heavily on generated code demonstrated weaker understanding of the underlying material. [InfoQ]infoq.comai coding skill formationAnthropic Study: AI Coding Assistance Reduces Developer…23 Feb 2026 — Anthropic research shows developers using AI assistance sco…
Research on students has raised similar questions. Studies investigating Copilot’s effects in educational settings increasingly focus not only on whether students can complete assignments but also on whether they can explain their solutions and transfer knowledge to new problems. [ACM Digital Library]dl.acm.orgACM Digital LibraryThe Effects of GitHub Copilot on Computing Students…by MIH Shihab · 2025 · Cited by 37 — This paper investigates ho…
These findings support a broader concern: AI assistance may sometimes substitute for learning rather than reinforce it. When that happens, productivity gains and knowledge gains diverge.
The review burden hidden behind apparent speed
A second reason speed can conceal shallow understanding is that generated code often shifts work rather than eliminating it.
Writing code is only one part of development. Someone must still:
- Verify correctness.
- Review assumptions.
- Evaluate security implications.
- Test unusual inputs.
- Ensure maintainability.
Studies and surveys increasingly describe a “verification burden” or “verification debt”: developers save time generating code but spend additional time checking whether it is trustworthy. [IT Pro]itpro.comDespite 96% of developers admitting they don't fully trust the functional correctness of AI-written code, many skip verification—primaril…
This becomes problematic when verification is skipped. Surveys have found that many developers do not consistently review AI-generated code despite expressing limited trust in its correctness. Other respondents reported that verifying AI-generated code can be more time-consuming than reviewing code written by colleagues because the reasoning behind the generated solution is often unclear. [TechRadar]techradar.comTech Radar Devs don't trust AI codeAlarmingly, less than half (48%) consistently check this code before committing it, opening the door to bugs and vulnerabilities. Even th…
In these situations, apparent productivity can be misleading. The speed comes from reducing visible effort at code creation while increasing hidden effort in validation and maintenance.
A revealing test: can the developer explain the code?
One practical way to distinguish genuine understanding from superficial acceptance is to ask developers to explain their AI-assisted work without looking at the generated output.
A developer who truly understands a Copilot suggestion should generally be able to explain:
- Why the chosen algorithm works.
- What assumptions it depends on.
- Which edge cases remain unhandled.
- How performance scales with larger inputs.
- What security risks might exist.
- How the implementation could be changed safely.
If those questions cannot be answered, the developer may be acting more as an approver than as an author.
This does not mean the code is necessarily bad. It means the human understanding behind the code may be weaker than the productivity statistics suggest.
Questions developers should answer before accepting a suggestion
Before accepting an AI-generated implementation, developers can ask a few simple questions:
Could I explain this to another engineer?
If not, additional review is probably required.
What problem is each major section solving?
Understanding should exist at the level of intent, not just syntax.
What would break if requirements changed?
Maintenance requires more than knowing that the current version works.
What assumptions does this code make?
Generated solutions often rely on unstated assumptions about inputs, environments, or libraries.
How would I test failure cases?
Understanding becomes visible when reasoning about things going wrong.
Could I reproduce the solution without the assistant?
The answer need not be yes every time, but the question reveals whether the tool is supporting learning or replacing it.
Why this matters for understanding artificial intelligence
The Copilot debate illustrates a broader lesson about AI systems. Artificial intelligence can increase output without proportionally increasing human understanding. A person may become faster, more productive, and more successful at completing tasks while simultaneously relying on reasoning they do not fully possess themselves. [arXiv]arxiv.orgarXiv The Impact of AI on Developer Productivity: Evidence from Git Hub CopilotThe Impact of AI on Developer Productivity: Evidence from GitHub CopilotFebruary 13, 2023…
That possibility does not negate the value of coding assistants. It simply changes how their benefits should be interpreted. Speed is a useful measure of performance, but it is an incomplete measure of expertise. When evaluating AI-assisted work, the crucial question is not only how quickly a task was completed, but whether the human involved can still explain, maintain, and improve the result after the assistant is gone.
Amazon book picks
Further Reading
Books and field guides related to Does faster coding mean better programming?. Use these as the next step if you want deeper reading beyond the article.
A Philosophy of Software Design
Emphasizes deep design understanding over coding speed.
Endnotes
-
Source: arxiv.org
Title: arXiv The Impact of AI on Developer Productivity: Evidence from Git Hub Copilot
Link: https://arxiv.org/abs/2302.06590Source snippet
The Impact of AI on Developer Productivity: Evidence from GitHub CopilotFebruary 13, 2023...
Published: February 13, 2023
-
Source: arxiv.org
Link: https://arxiv.org/pdf/2302.06590Source snippet
Further investigations into the productivity...Read more...
-
Source: arxiv.org
Link: https://arxiv.org/abs/2509.20353Source snippet
Developer Productivity With and Without GitHub Copilot: A Longitudinal Mixed-Methods Case StudySeptember 24, 2025...
Published: September 24, 2025
-
Source: third-bit.com
Link: https://third-bit.com/2026/05/20/twelve-ways-to-be-wrong/Source snippet
The task was...Read more...
-
Source: arxiv.org
Link: https://arxiv.org/html/2602.03593v1Source snippet
Developer Perspectives on Productivity with AI Coding...Feb 3, 2026 — In the age of AI coding assistants, it has become even more import...
-
Source: arxiv.org
Link: https://arxiv.org/abs/2208.14613Source snippet
How Readable is Model-generated Code? Examining Readability and Visual Inspection of GitHub CopilotAugust 31, 2022...
Published: August 31, 2022
-
Source: infoq.com
Title: ai coding skill formation
Link: https://www.infoq.com/news/2026/02/ai-coding-skill-formation/Source snippet
Anthropic Study: AI Coding Assistance Reduces Developer...23 Feb 2026 — Anthropic research shows developers using AI assistance sco...
-
Source: dl.acm.org
Link: https://dl.acm.org/doi/full/10.1145/3702652.3744219Source snippet
ACM Digital LibraryThe Effects of GitHub Copilot on Computing Students...by MIH Shihab · 2025 · Cited by 37 — This paper investigates ho...
-
Source: techradar.com
Title: Tech Radar Devs don’t trust AI code
Link: https://www.techradar.com/pro/devs-dont-trust-ai-code-but-many-say-they-still-dont-check-it-anywaysSource snippet
Alarmingly, less than half (48%) consistently check this code before committing it, opening the door to bugs and vulnerabilities. Even th...
-
Source: github.com
Title: Git Hub · Change is constant
Link: https://github.com/Source snippet
GitHub keeps you ahead. · GitHubFrom your first line of code to final deployment, GitHub provides AI and automation tools to help you bui...
-
Source: github.com
Link: https://github.com/features/copilotSource snippet
GitHub Copilot · Your AI pair programmerCopilot in your editor does it all, from explaining concepts and completing code, to proposing ed...
-
Source: docs.github.com
Title: [code review]({{ ‘code-review/’ | relative_url }})
Link: https://docs.github.com/en/copilot/concepts/agents/code-reviewSource snippet
GitHub Copilot code reviewCopilot code review reviews code written in any language, and provides feedback. It reviews your code from mult...
-
Source: learn.github.com
Link: https://learn.github.com/learning-pathways/github-copilotSource snippet
of GitHub Copilot (Learning Pathway)GitHub Copilot Chat acts as a real‑time collaborator, helping developers reason through logic, valida...
-
Source: arxiv.org
Link: https://arxiv.org/pdf/2302.00438Source snippet
An Empirical Study on GitHub Copilotby A Mastropaolo · 2023 · Cited by 260 — In this paper we present an empirical study in which we aim...
-
Source: arxiv.org
Link: https://arxiv.org/html/2504.16485v1Source snippet
On Developers' Self-Declaration of AI-Generated CodeApr 23, 2025 — This study intends to understand the ways developers use to self-decla...
-
Source: github.blog
Link: https://github.blog/ -
Source: github.blog
Title: Does Git Hub Copilot improve code quality?
Link: https://github.blog/news-insights/research/does-github-copilot-improve-code-quality-heres-what-the-data-says/Source snippet
Here's what...Nov 18, 2024 — Findings in our latest study show that the quality of code written with GitHub Copilot is significantly mor...
-
Source: github.blog
Title: survey reveals ais impact on the developer experience
Link: https://github.blog/news-insights/research/survey-reveals-ais-impact-on-the-developer-experience/Source snippet
Survey reveals AI's impact on the developer experienceJun 13, 2023 — In previous research we conducted, 87% of developers reported that t...
-
Source: cacm.acm.org
Title: measuring github copilots impact on productivity
Link: https://cacm.acm.org/research/measuring-github-copilots-impact-on-productivity/Source snippet
GitHub Copilot's Impact on Productivity15 Feb 2024 — A case study asks Copilot users about the tool's impact on their productivity, and s...
-
Source: dl.acm.org
Link: https://dl.acm.org/doi/full/10.1145/3709353Source snippet
AI Transformation of Developer's Routine by 2030by K Qiu · 2025 · Cited by 34 — In this article, we provide a comparative analysis betwee...
-
Source: itpro.com
Link: https://www.itpro.com/software/development/software-developers-not-checking-ai-generated-code-verification-debtSource snippet
Despite 96% of developers admitting they don't fully trust the functional correctness of AI-written code, many skip verification—primaril...
Additional References
-
Source: linkedin.com
Link: https://www.linkedin.com/posts/aagupta_41-of-all-code-shipped-in-2025-was-ai-generated-activity-7438810992651743232-II6uSource snippet
AI-Generated Code Defects Rise, PMs Must Own Intent... burden of verification shifts from syntax to systemic outcomes. Relying on automat...
-
Source: linkedin.com
Link: https://www.linkedin.com/posts/drelleobrien_more-code-less-validation-risk-factors-activity-7413966333069131776-Yfj5Source snippet
Elle O'Brien's PostWhat we should do, is stop accepting code from any source—AI or human—without knowledgeable human review. That it comp...
-
Source: cut-the-saas.com
Link: https://cut-the-saas.com/ai/[generative-aiSource snippet
Gen AI Impact: 56% Faster Dev TasksHow much faster did developers code with GitHub Copilot in this study? The group using Copilot complet...
-
Source: xebia.com
Link: https://xebia.com/blog/github-copilot-productivity/Source snippet
GitHub Copilot & ProductivityRob has a strong focus on ALM and DevOps, automating manual tasks and helping teams deliver value to the end...
-
Source: medium.com
Link: https://medium.com/%40reliabledataengineering/ai-is-writing-46-of-all-code-github-copilots-real-impact-on-15-million-developers-787d789fcfdc -
Source: git-scm.com
Link: https://git-scm.com/ -
Source: zenml.io
Link: https://www.zenml.io/llmops-database/improving-contextual-understanding-in-github-copilot-through-advanced-prompt-engineeringSource snippet
Improving Contextual Understanding in GitHub Copilot...This case study examines how GitHub's machine learning researchers and engineers...
-
Source: linkedin.com
Link: https://www.linkedin.com/posts/sanjoyghosh82_transforming-software-development-evaluating-activity-7213884338935918594-oNGgSource snippet
How GitHub Copilot boosts developer productivity... study from Cornell University: Pros: - Time Savings: Developers can save up to 50% on...
-
Source: researchgate.net
Link: https://www.researchgate.net/publication/368473822_The_Impact_of_AI_on_Developer_Productivity_Evidence_from_GitHub_CopilotSource snippet
GitHub Copilot as an AI partner programmer completed tasks 55.8% faster than others. Furthermore, a survey study on Copilot by Liang et a...
-
Source: ksred.com
Title: ai for coding why most developers are getting it wrong and how to get it right
Link: https://www.ksred.com/ai-for-coding-why-most-developers-are-getting-it-wrong-and-how-to-get-it-right/Source snippet
AI for Coding: Why Most Developers Get It Wrong (2025 Guide)28 July 2025 — The data backs this up: while 76% of developers are using or p...
Published: July 2025
Topic Tree



